1. Field of the Invention
The present invention relates to input methods and input devices suited for operating, for example, portable electronic apparatuses.
2. Description of the Related Art
It is difficult to provide a keyboard with portable electronic apparatuses, such as PDAs (Personal Digital Assistants), compared to typical computers. Input devices, such as touch panels, are therefore constructed to realize various inputs by touching a panel with an object, such as a finger and a special pen.
The touch panel is formed on the display panel, such as a liquid crystal display panel, where operation buttons, a keyboard, and the like are displayed. When one of the buttons or a key on the keyboard is touched, even though the touch panel has relatively a small area, a complicated input process can be realized by assigning a function to the corresponding button or key.
However, known touch panels are constructed to accept an input via direct contact on the front surface of the display panel with the object. This causes a variety of problems. For example, touching the display panel directly to operate it may smudge the front surface of the display panel. The smudges become worse, making characters and graphics on the display panel hard to recognize. This requires occasional cleaning of the front surface of the display panel with a cloth or the like.
In addition, when touching the display panel with the finger to operate it, the sizes of the operation buttons shown on the display panel should not be less than the width of the finger. To be specific, a touch panel in which a plurality of operation buttons is aligned with a pitch narrower than the width of a finger to operate it by touching the display position of a desired operation button has been constructed. When using this touch panel, however, the user may accidentally touch several buttons simultaneously or may cover the entirety of one operation button with his/her finger. Hence, the user cannot easily recognize which operation button corresponds to the position being touched with the finger. This reduces the operability of the touch panel.